3D star-shaped morphological modify carbon-nitrogen compounds of zeolitic imidazolate frameworks for Microsupercapacitors

To enhance supercapacitor performance, it is crucial to design electrode materials that are abundant in active sites and incorporate specific functional groups to facilitate rapid ion transport. This study demonstrates the synthesis of star-shaped CoZn-ZIFs using a green method. The derived CoZn-NCs exhibit a wealth of effective functional groups, achieved through the rational tuning of elemental proportions and calcination temperatures. When utilized as a supercapacitor electrode, the Co 1 Zn 1 -NCs/550 electrode attained a specific capacitance of 928 F g⁻¹ at a current density of 0.1 A g⁻¹. Density functional theory (DFT) results further reveal a narrow energy band, suggesting that CoZn-NCs possess good conductivity. A solid-state flexible micro-supercapacitor was constructed using the Co 1 Zn 1 -NCs/550 electrode material. This device exhibited an area capacitance of 637.5 mF cm⁻² accompanied by remarkable electrochemical durability with 97% capacitance retention performance after 5000 cycles at a current density of 1 mA cm⁻². Furthermore, devices connected in series and/or parallel successfully powered light-emitting diodes for several minutes, as demonstrated in a video recording, confirming their potential for practical applications. This work offers promising insights into enhancing energy storage.